Abstract:In Clintonia udensis Trautv. et Mey, the ovule is of anatropous type, having two integuments. The nucellus is tenuinucellate with unicellular archesporium derived from the hypodermal cell at the tip of the young nucellus acting directly as the megaspore mother cell. The division of the megaspore mother cell results in 1+3 arrangement, the three nuclei in the chalazal end degenerate and fuse in various ways.